Improving Hep C Treatment Via Individualized Therapy

A mathematical model developed by researchers at Loyola University in Chicago can predict the length of time patients with hepatitis C virus (HCV) must remain on direct-acting antiviral (DAA) drugs to achieve sustained virologic response, according to a new study.

 

The investigators used early viral kinetic analysis to test study participants—58 people with HCV being treated at three medical centers in France—for blood levels of the virus at the start of the study, on the second day of treatment, every other week, at the end of the study and then 12 weeks after the study concluded. The patients were each on 12-week drug regimens: sofosbuvir (Sovaldi, Gilead) and simeprevir (Olysio, Janssen), sofosbuvir and daclatasvir (Daklinza, Bristol-Myers Squibb), or ledipasvir-sofosbuvir (Harvoni, Gilead).

 

They found that frequent blood testing could predict HCV levels, and identify which patients would receive cure within six, eight, 10, 12 and 13 weeks of therapy, respectively. For the single patient in the study who relapsed, the modeling suggested that he would have benefited from an additional week of ledipasvir-sofosbuvir. Adjusting treatment according to the model would reduce medication costs by 16% to 20% per 1,000 patients receiving treatment, the study found (J Hepatol 2016 Feb 20. doi: 10.1016/j.jhep.2016.02.022. [Epub ahead of print]).

 

“This is the first time this approach has been tested in hepatitis C patients undergoing DAA treatment,” said co-author Harel Dahari, PhD, an assistant professor of hepatology at Loyola, in an interview with SPC. “This initial study is very encouraging. We have found a way to not only shorten the treatment, but extend it in some patients who may need that.”

 

Dr. Dahari explained that, based on the group’s experience, there are two phases of viral load decline with current HCV therapies. “After just two days on therapy, there is a very sharp, rapid decline. Then, there is a longer, slower decline. In order to predict the point of cure, we need to know where the viral load was before treatment, then after two days and then a few more time points to define the second phase. Then we can extrapolate those curves and individualize the treatment.”

 

Before this approach can be adopted broadly, Dr. Dahari said, prospective studies are needed. But if it proves accurate, it has the potential to offer significant savings. “In France, based on current prices for the drugs, we predicted that it would save almost 1 million Euros for every 100 patients treated,” he said.